The present disclosure is related generally to the field of dental treatment. More particularly, the present disclosure is related to the fabrication of polymeric dental appliances for orthodontic dental treatment.
Many dental treatments involve repositioning misaligned teeth and changing bite configurations for improved cosmetic appearance and dental function. Repositioning can be accomplished, for example, by applying controlled forces to one or more teeth over a period of time. Repositioning teeth for aesthetic or other reasons has been accomplished by wearing what are commonly referred to as “braces.” Braces typically encompass a variety of hardware such as brackets, archwires, ligatures, and O-rings.
Some dental processes use polymeric dental positioning appliances, rather than braces, for realigning teeth. Such appliances may, for example, utilize a thin shell of material having resilient properties, referred to as an “aligner” that generally conforms to a patient's teeth but is slightly out of alignment with the present (e.g., initial) tooth configuration. Placement of such an appliance over the teeth provides controlled forces in specific locations to gradually move the teeth into a new configuration. Repetition of this process with successive appliances that provide progressive configurations eventually move the teeth through a series of intermediate arrangements to a final desired arrangement.
Many processes for forming such dental appliances utilize thermoplastic material. These materials have a long period in which the forming of the dental appliance can take place, and therefore are desirable materials.